In the past four years we have created a set of sophisticated and realistic laboratory simulations for use in freshman- and sophomore-level chemistry classes and laboratories called Virtual ChemLab. We have completed simulations for Inorganic Qualitative Analysis, Organic Synthesis and Organic Qualitative Analysis, Fundamental Experiments in Quantum Chemistry, Gas Properties, Titration Experiments, and Calorimetry. The purpose of our simulations is to reinforce concepts taught in the classroom, provide an environment for creative learning, and emphasize the thinking behind instructional laboratory experiments. We have used the inorganic and organic simulations extensively with thousands of students in our department at Brigham Young University. Some important learnings from our evaluation include: (i) students enjoy using these simulations and find them to be an asset in learning effective problem-solving strategies, (ii) students like the fact that they can both reproduce experimental procedures and expl...